Drilling
Underbalanced Drilling: General Issues
![Underbalanced Drilling General Issues](/wp-content/uploads/2022/06/underbalanced-drilling-general-issues-780x470.webp)
Well Logging of Underbalanced Holes
Most logging tools are sensitive to the type of fluid present at the time of the logging. Depending on the level of underbalance, the wireline tools might have to be run through special lubricators to maintain underbalanced conditions.
As technology changes, service companies are continually improving their existing logging tools. Therefore, you should always check with your service company to learn more about the most recent tools available for wells drilled with gas or gasified liquids. Table 1 summarizes the applicability of various logging tools in underbalanced drilling.
Table 1: Well logging in air and gasified liquid drilling.
Logging Technique | Air Drilling | Gasified Liquids Drilling |
---|---|---|
Spontaneous Potential Log | No | No |
Gamma Ray Log | Yes | Yes |
Neutron Log | Yes (with correction) | Yes (with correction) |
Density Log | Yes (with correction) | Yes (with correction) |
Resistivity Log | No | No |
Induction Log | Yes | Yes |
NMR Log | Yes | Yes |
Acoustic Log | No | No |